Sectional forming roll having improved strength and stability

ABSTRACT

Either one or both of an upper roll and a lower roll for cooperatively forming a ribbon of sheet metal into a desired form is divided into a plurality of driving sections and idling sections and a needle roller bearing is used for one of the two sets of bearings provided on a sleeve of each idling section fixedly mounted on a driving shaft, and further a labyrinth packing is used for one of two sets of oil seals, whereby a forming roll, well lubricated and having improved strength and stability can be obtained.

United States Patent Kida et al.

[ Sept. 11, 1973 SECTIONAL FORMING ROLL HAVING IMPROVED STRENGTH AND STABILITY [75] Inventors: Kaneaki Kida, Yasugi; Kazuyoshi Ida, Yonago, both of Japan [73] Assignee: Hitachi Metals, Ltd., Tokyo, Japan [22] Filed: June 8, 1971 [21] Appl. No.: 151,060

[30] Foreign Application Priority Data Sept. 4, 1970 Japan 45/77077 [52] U.S. Cl a 72/43, 72/236 [51] Int. Cl B21b 27/08 [58] Field of Search 72/179, 180, 181,

[56] References Cited UNITED STATES PATENTS 1,215,749 2/1917 Vandergrift 308/208 1,304,430

5/1919 Wickersham 308/208 1,836,339 12/1931 Ronk 308/208 2,232,967 2/1941 Price et al. 308/233 3,107,718 10/1963 Ruple i 72/182 3,515,448 6/1970 Williams et al. 308/208 FOREIGN PATENTS OR APPLICATIONS 1,075,528 2/1960 Germany 72/182 Primary Examiner-Charles W. Lanham Assistant ExaminerE. M. Combs Attorney-Craig, Antonelli & Hill [57] ABSTRACT Either one or both of an upper roll and a lower roll for cooperatively forming a ribbon of sheet metal into a desired form is divided into a plurality of driving sections and idling sections and a needle roller bearing is used for one of the two sets of bearings provided on a sleeve of each idling section fixedly mounted on a driving shaft, and further a labyrinth packing is used for one of two sets of oil seals, whereby a forming roll, well lubricated and having improved strength and stability can be obtained.

9 Claims, 4 Drawing Figures Patented Sept. 11, 1973 3,757,554

4 Sheets-Sheet 1 i 7 41mm x E I I I \I E i I J r n Q i ff s R Q k m INVENTORS BY 51 RMM 5 ML ATTORNEYS Patented Sept. 11, 1973 3,757,554

4 Sheets-Sheet 3 INVENTOR$ KHNERN \QDH QND knzwlosm 1BR Civ a 2r ATTORNEYS Paiented Sept. 11, 1973 3,757,554

4 Sheets-Sheet 4 INVENTORS KRNEHN \MDR Fm vkqzualosv IDH BY 5% RM av 19k ATTORNEYS SECTIONAL FORMING ROLL HAVING IMPROVED STRENGTH AND STABILITY This invention relates to a sectional forming roll which is made up of a plurality of sections and used for at least one of two rolls of each of a multiplicity of roll stands through which a strip or ribbon of sheet metal is gradually formed into a desired form.

A sectional forming roll is constructed so as to reduce the power required for the formation of a ribbon of sheet metal, to minimize the flaw and residual stress in the formed material by decreasing the peripheral speed differential between the ribbon of sheet metal and the roll, to be resistive to wear, to maintain its strong forming force and to be easy to assemble and maintain;

As an example of the sectional forming roll, reference can be made to one which has been used in tube mills. ln a tube mill comprising a sectional forming roll, the lower roll is made up of three sections, i.e. a driving section and independently rotatable idling sections arranged respectively at the opposite ends of said driving section. Each of the idling sections comprises a sleeve mounted on a driving shaft, a pair of thrust roller bearings provided on said sleeve, a hollow portion formed between said thrust roller bearings for storing lubricating oil, oil seals provided forwards and to the rear of said pair of bearings and members for retaining said oil seals. This type of sectional forming roll is described in U.S. Pat. No. 3,107,718.

The conventional sectional forming roll of the type described, however has the disadvantage that, since the surface of the idling section thereof has a large curvature and hence the radius of the same varies, largely, axially, the thickness of the idling section on the smaller diameter side between the outer diameter of said idling section and the outer diameter of a thrust roller bearing on said smaller diameter side of the idling section becomes small and the strength of the roll material is reduced. This is particularly so in case of the sectional forming roll of the prior invention which is made of a quench hardened steel having a high hardness." On the other hand, if the thickness of the idling section at said portion is increased, the distance between the two thrust roller bearings cannot be increased, so that the moment of load imposed on the thrust roller bearings becomes large, rendering the idling section unstable. The temperature of the sectional forming roll occasionally rises during the rolling operation and in the conventional sectional roll the resultant thermal expansion of the idling section cannot be absorbed due to the fact that the idling section comprises only thrust roller bearings. Therefore, the strength and useful life of the bearings are impaired by the increasing axial component of force. The conventional sectional roll also has the disadvantage of being liable to binding due to deterioration of lubricating oil during use of the roll for an extended period, which is attributable to the type of the oil seals used therein.

A first object of the present invention is to provide a sectional forming roll having idling sections, the thickness of which between the outer diameter thereof on the smaller diameter side and the outer diameter of a bearing is large and which, therefore, is very strong.

A second object of the invention is to provide a sectional forming roll having idling sections in which the distance between a needle roller bearing and a thrust roller bearing is made sufficiently large with respect to the moment of load.

A third object of the invention is to provide a sectional forming roll having idling sections in which are provided a needle roller bearing and a thrust roller bearing, whereby the axial expension and contraction of the idling section due to thermal expansion can be absorbed by said needle roller bearing.

A fourth object of the invention is to provide a sectional forming roll in which one of two oil seals provided in each of idling sections consists of a labyrinth packing so as to ensure satisfactory lubrication at all times.

An additional object of the invention is to make it possible to use a sectional roll having idling sections for small-sized rolls and to thereby expand the range of application of said sectional roll, by using a needle roller bearing on the smaller diameter side of each idling section. According to the invention, there is provided an improved sectional forming roll having higher strength and better stability, which overcomes the drawbacks of the conventional sectional forming rolls and which comprises idling sections each of which includes a needle roller bearing provided on a sleeve, mounted on a driving shaft, on the smaller diameter side and a thrust roller bearing provided on said sleeve on the larger diameter side thereof, and a labyrinth packing used for the oil seal disposed exterior of said thrust roller bearmg.

FIG. 1 is a side elevation, partially in section, ofa sectional forming roll according to the present invention;

FIG. 2 is a fragmentary cross-sectional view of the idling roll shown in FIG. 1;

FlG. 3 is a side elevation, partially in section, ofa sectional forming roll having two sections; and

FIG. 4 is a side elevation, partially in section, of a sectional forming roll having a multiplicity of sections.

An embodiment of the present invention will be described with reference to FIGS. 1 and 2. Reference numeral l designates an upper roll rotatably mounted on a spindle 2. Reference numeral'4 designates a lower roll which is made up of a driving section 5 and independently rotatable idling flange sections 6 and 7. Reference numeral 8 designates a driving shaft to which the driving section 5 of the lower roll is secured by means of a key 9. Reference numeral 10 designates a strip or ribbon of sheet steel to be formed. The flange sections 6 and 7 are symmetrical with each other and of the same construction, each comprising a flange roll member 11, a sleeve 12, a dual thrust taper roller bearing 13, a needle roller bearing 14, side covers 15 and 16, an oil'seal 17, a labyrinth packing 18, a supporting plate 19 and a stopper ring 20, rotatably supported through the dual thrust taper roller bearing 13 and the needle roller bearing 14. The sleeve 12 is secured to the driving shaft 8 by means of the key 9. The needle roller bearing 14 is provided on the sleeve 12 on the smaller diameter side of the flange roll member 11 and, in order to prevent axial displacement, the inner race 21 thereof is held in abutting engagement with the side cover 15 and the outer race 22 thereof is set in position by the stopper ring 20. The oil seal 17 is provided on the smaller diameter side of the flange roll member 1 l for sliding movement on the side cover 15. The dual thrust taper roller bearing 13 is provided on the sleeve 12 on the larger diameter side of the flange roll memher 11 and held against axial displacement by the side cover 16. The labyrinth packing 18 is supported by the dual thrust roller bearing 13 and the supporting plate 19 and is slidable on the side cover 16. An oil passage 23 is-defined by the flange roll member 11 and the sleeve 12 between the dual thrust roller bearing 13 and the needle roller bearing 14, for the passage oflubricating oil therethrough. Reference numeral 24 designates a lubricating oil feed passage for feeding the lubricating oil from an oil cup 25.

With the construction described above, when the driving shaft 8 is driven, the ribbon of sheet steel 10 is advanced by the rotation of the upper roll 1 and the lower roll 4 while being clamped between said upper roll 1 and the driving section 5 of said lower roll 4.

The flange sections 6 and 7 are arranged in positions where the peripheral speed differential thereof with respect to the driving section 5 is large, and are rotatably mounted on the driving shaft 8. Therefore, these flange sections are only effective for bending the ribbon of sheet steel 10 and are driven through said ribbon of sheet steel 10 at the same speed as that of the latter. The ribbon of sheet steel 10 is subjected to an extremely large force during shaping. In addition, since the bearings, the sleeve, etc. are interposed between the flange roll members 11 of the flange sections 6 and 7 and the driving shaft 8, the thickness of the smaller diameter side of the flange roll member 11 becomes small, and moreover the flange roll member 11 is made of a quench hardened steel and hence quite weak. Thus, there is the danger of breakage. Particularly, the thickness at the portion A of the smaller diameter side of the flange roller member 11 becomes small. With this in view, according to the invention, use is made of the needle roller bearing 14 which is small in radius and receives only a radial load, whereby the thickness at the portion A of the flange roll member 11 can be made large and, therefore, the distance between the dual taper roller bearing 13 and the needle roller bearing 14 can be increased. Also, since the loads imposed on the bearings by moment of load can be selected in a safe range, the accuracy of the flange sections 6 and 7 can be maintained and the useful lives thereof can be prolonged.

For instance, the outer diameter of the needle roller bearing 14 corresonding to a thrust roller bearing having an outer diameter of 460 mm is 380 mm and thus the thickness at the portion A of the flange roll member 11 can be as large as about 40 mm, which imparts an improved strength to the flange roll member and enables the sectional forming roll of the invention to be applied to the conventional small rolls for which a flanged sectional forming roll could not be used for the reason that a thrust roller bearing was used instead of the needle roller bearing. Consequently, the rangcof application of the flanged sectional roll can be expanded to the field of production of relatively small size and shaped articles. I

In conventional sectional forming rolls using only such a thrust taper roller bearing 13, the axial expansion of the flange sections 6 and 7 has not been permitted as there is provided no means to allow for such axial expansion. Therefore, when the flange sections 6 and 7 expand axially, the axial gap between the race and the rollers has been reduced, making it impossible to maintain a proper axial gap of the bearing, with the result that the useful life of the bearing is shortened and the bearing is liable to binding. According to the present invention, however, since the needle roller bearing 14 is used, it is possible to deal with such axial expansion caused by temperature rise during use. Namely, the thermal expansion of the flange sections 6 and 7 which is greater as the sizes of said flange sections becomes large, can be absorbed by the needle roller bearing 14, whereby the strength of the flange sections can be im proved and the useful life of the same can be prolonged. Further, according to the present invention the labyrinth packing 18 having a very small gap is used for an oil seal to be disposed exterior to each of flange sections 6 or 7, whereby the deteriorated oil interior of the flange section is successively discharged to the outside to ensure satisfactory lubrication and the possible binding of the flange section, under an extremely large shaping force, which is imposed on the flange section depending upon the condition of the ribbon steel and the twisting of the same, can be prevented.

Referring to FlG. 3 there is shown another form of the sectional forming roll of the present invention which is made up of two sections. In P16. 3, reference numeral 26 designates an upper roll fixedly mounted on a spindle 27. Reference numeral 28 designates a lower roll made up of two sections, i.e. a driving section 29 and a flange section 30. The driving section 29 is fixedly mounted on a driving shaft 31. The flange section 30 comprises a flange roll member 33, a sleeve 34, a dual thrust taper roller bearing 35, a needle roller bearing 36, side covers 37 and 38, an oil seal 39, a labyrinth packing 40 and a supporting plate 41. The sleeve 34 is secured to the driving shaft 31 by means of a key 32. The dual thrust taper roller bearing 35 is provided on the sleeve 34 on the larger diameter side of the flange roll member 33 and secured by the side cover 37. The needle roller bearing 36 is provided on the smaller diameter side of the flange roll member 33 and secured by the side cover 38. The oil seal 39 is provided on the side cover 38 on the side closer to the needle roller bearing 36 for sliding movement thereon. The labyrinth packing 40 is supported by the dual thrust taper roller bearing 35 and the supporting plate 41, and is slidable on the side cover 38. Further, a lubricating oil passage is provided for lubricating the dual thrust taper roller bearing 35 and the needle roller bearing 36 from an oil cup or the like. Reference numeral 42 designates a strip or ribbon of sheet steel to be formed.

With the construction described above, when the rib bon of sheet steel 42 is inserted between the upper roll 26 and the lower roll 28 which are respectively driven by the spindle 27 and the driving shaft 31, it is formed into a desired form by being engaged and clamped by said upper roll 26 and the driving section 29 of said lower roll 28, and thrust forward.

in this case, the flanged lower roll of the invention has the same advantages as described with reference to the embodiment of FIGS. 1 and 2, and the use of the needle roller bearing 36 and the labyrinth packing 40 also brings about the same advantages as described previously.

FIG. 4 shows still another form of the sectional forming roll of the invention which is made up of a multiplicity of sections. In FlG. 4, reference numeral 43 designates an upper roll which is made up of driving sections 45, 46 and 47 fixedly mounted on a driving shaft 44, and flange sections 48 and 49 rotatably mounted on said driving shaft 44. Reference numeral 50 designates a lower roll made up of five sections, i.e. driving sections 51 and 52 and flange sections 53, 54 and 55. The driving sections 51 and 52 and the flange sections 53 and 54 are respectively of the same construction and symmetrical with each other. The driving sections 51 and 52 are secured to the driving shaft 56 by means of a key 57, to be driven thereby. The flange section 53 comprises a flange roll member 58, a sleeve 59, a dual thrust taper roller bearing 60, a needle roller bearing 61, side covers 62 and 63, an oil seal 64, a labyrinth packing 65 and a supporting plate 66. The sleeve 59 is secured to the driving shaft 56. The dual thrust roller bearing 60 is provided on the sleeve 59 on the larger diameter side of the flange roll member 58 and tightly fixed by the side cover 62. The needle roller bearing 61 is provided on the smaller diameter side of the flange roll member 58 and tightly fixed by the side cover 63. The oil seal 64 is provided on the flange roll member 58 on the side closer to the needle roller bearing 61 and slidable on the side cover 63. The labyrinth packing 65 is supported by the dual thrust taper roller bearing 60 and the supporting plate 66, and is slidable on the side cover 62. The dual thrust roller bearing 60 and the needle roller bearing 61 are lubricated by lubricatint oil supplied thereto from a grease cup or the like through an oil passage. The flange section 55 comprises a flange roll member 67, a sleeve 68, needle roller bearings 69 and 70, a spacer 71 and a side cover 72. The sleeve 67 is secured to the driving shaft 56 by means of a key 57. On the sleeve 68 are provided the needle roller bearing 69, the spacer 71 and the needle roller bearing 70, which are tightly secured by the side cover 72.

The flange section 55 has different diameter portions but is transversely symmetrical in shape, so that the axial loads are offset by each other and only a vertical load is imposed thereon. Therefore, the needle roller bearings 69 and 70 are used in this flange section. An arrangement is made to lubricate the bearings 69 and 70. Reference numeral 73 designates a strip or ribbon of sheet steel to be formed.

The flange sections 53, 54 and 55 rotate freely through the dual thrust taper roller bearing 60, the needle roller bearing 61 and the needle roller bearings 69 and 70, even when the driving shaft 56 rotates.

With the construction described above, when the ribbon of sheet steel 73 is inserted between the upper roll 43 and the lower roll 50 which are respectively driven by the driving shafts 44 and 56, it is formed into a desired form and thrust forward.

In this case, the flanged lower roll of the invention has the same advantage as described previously, and

the use of the needle roller bearing 61 and the labyrinth packing 65 also brings about the same advantage as mentioned with reference to the embodiment of FIGS. l and 2.

The flange sections 48 and 49 of the upper roll 43 may be of the same construction as the flange section 55.

Although in the embodiments described and illustrated herein the sectional forming roll of the invention has been described as applied to the lower roll, it will he understood that it may similarly be applied to the upper roll.

According to the present invention, as described above, a needle roller bearing is used for one of two sets of bearings provided in a flange section, which is located on the smaller diameter side of said flange section, and further a labyrinth packing is used for one of two sets of oil seals provided in said flange section, which is located on the outer side, whereby the thickness of the smallest thickness portion of the flange section around the bearing can be made large, even when the diameter of said flange section is small, and a sufficient strength of flange section at said portion can be secured even under severe forming conditions. Furthermore, since according to the invention the idling flanged roll can be used for a small diameter roll which has been used as a fixed roll, the range of application of the sectional forming roll can be expanded. It is also to be noted that according to the invention the distance between the axially arranged bearings can be made large, so that the stability of the roll against the moment of load can be enhanced, which will in turn make it possible to maintain the accuracy of the sectional forming roll and to extend the service life of the same. It is also to be noted that according to the invention the axial thermal expansion of the sectional forming roll can be absorbed by the axial displacement of said sectional roll between the inner race and the needle roller bearing. Therefore, in no case will an unreasonable force be exerted on the bearings and a satisfactory operation of the roll can be ensured. Another advantage of the invention is that, since a labyrinth packing is used for one of the two oil seals provided in the sectional forming roll, the deteriorated oil can be removed through said labyrinth packing and a fresh lubricating oil can be constantly supplied to the bearings to ensure satisfactory lubrication during use of the roll. As described above, according to the invention it is possible to obtain an improved sectional forming roll which has excellent strength and stability.

What is claimed is:

1. A sectional forming roll including a plurality of drlving sections and idling sections, used as one of an upper roll, a lower roll and both an upper roll and a lower roll in a multiplicity of roll stands, for forming a ribbon of sheet metal into a predetermined shape, said idling sections each comprising a sleeve fixedly mounted on a driving shaft, a flange roll member having an axially varying diameter, two sets of bearings provided between said sleeve and said flange roll member with said bearings provided on a smaller diameter side of said flange roll member being needle roller bearings and the other bearings provided on a larger diameter side of said flange roll member being thrust roller bearings, said needle roller bearings and said thrust roller bearings being tightly secured by side covers respectively and being lubricated with lubricating oil supplied through a first oil passage extending therebetween and a second oil passage leading to the exterior from said first oil passage, and a set of oil seals exteriorly provided to each of said needle roller bearings and said thrust roller bearings, one of said oil seals provided on an exterior side being supported by a supporting plate, and said idling section being rotatably supported by said needle roller bearings and said thrust roller bearings.

2. A sectional forming roll according to claim 1, wherein said one of said oil seals provided on an exterior side includes a labyrinth packing.

3. A sectional forming roll according to claim 1, wherein said smaller diameter side of said flange roll member is adjacent to at least one driving section, such that said needle roller bearing is subjected only to radial forces.

4. An idling section roll for use in a sectional forming roll for forming a metal sheet into a predetermined shape comprising a flange roll member having an axially varying diameter, said diameter being small at a first end of said member and large at a second end of said member, a sleeve fixedly mounted on a driving shaft extending through said member, at least one set of needle roller bearings disposed at the small first end of said member, and at least one set of thrust roller bearings disposed at the large second end of said member, wherein said idling section member is rotatabiy supported by said needle roller bearings and said thrust roller bearings.

5. An idling section roll according to claim 4, further including a first oil passage extending between said needle roller bearings and said thrust roller bearings, a second oil passage extending from said first oil passage to the exterior of said member and a set of oil seals disposed exteriorly to said needle roller bearings and said thrust roller bearings.

6. An idling section roll according to claim 5, wherein one of said oil seals is supported on an exterior side of said member by a supporting plate.

7. An idling section roll according to claim 6, wherein said one of said oil seals includes a labyrinth packing.

8. A sectional forming roll according to claim I, including a plurality of driving sections and idling sections, wherein at least one second flange roll member is disposed on said driving shaft between at least one of a pair of said driving sections,said second flange roll member being axially symmetrical with a small diameter at each end thereof and being rotatably supported by at least two sets of needle roller bearings, each said set disposed at each small diameter end of said second member.

9. A sectional forming roll according to claim 8,

wherein said needle roller bearings are lubricated. 

1. A sectional forming roll including a plurality of dr1ving sections and idling sections, used as one of an upper roll, a lower roll and both an upper roll and a lower roll in a multiplicity of roll stands, for forming a ribbon of sheet metal into a predetermined shape, said idling sections each comprising a sleeve fixedly mounted on a driving shaft, a flange roll member having an axially varying diameter, two sets of bearings provided between said sleeve and said flange roll member with said bearings provided on a smaller diameter side of said flange roll member being needle roller bearings and the other bearings provided on a larger diameter side of said flange roll member being thrust roller bearings, said needle roller bearings and said thrust roller bearings being tightly secured by side covers respectively and being lubricated with lubricating oil supplied through a first oil passage extending therebetween and a second oil passage leading to the exterior from said first oil passage, and a set of oil seals exteriorly provided to each of said needle roller bearings and said thrust roller bearings, one of said oil seals provided on an exterior side being supported by a supporting plate, and said idling section being rotatably supported by said needle roller bearings and said thrust roller bearings.
 2. A sectional forming roll according to claim 1, wherein said one of said oil seals provided on an exterior side includes a labyrinth packing.
 3. A sectional forming roll according to claim 1, wherein said smaller diameter side of said flange roll member is adjacent to at least one driving section, such that said needle roller bearing is subjected only to radial forces.
 4. An idling section roll for use in a sectional forming roll for forming a metal sheet into a predetermined shape comprising a flange roll member having an axially varying diameter, said diameter being small at a first end of said member and large at a second end of said member, a sleeve fixedly mounted on a driving shaft extending through said member, at least one set of needle roller bearings disposed at the small first end of said member, and at least one set of thrust roller bearings disposed at the large second end of said member, wherein said idling section member is rotatably supported by said needle roller bearings and said thrust roller bearings.
 5. An idling section roll according to claim 4, further including a first oil passage extending between said needle roller bearings and said thrust roller bearings, a second oil passage extending from said first oil passage to the exterior of said member and a set of oil seals disposed exteriorly to said needle roller bearings and said thrust roller bearings.
 6. An idling section roll according to claim 5, wherein one of said oil seals is supported on an exterior side of said member by a supporting plate.
 7. An idling section roll according to claim 6, wherein said one of said oil seals includes a labyrinth packing.
 8. A sectional forming roll according to claim 1, including a plurality of driving sections and idling sections, wherein at least one second flange roll member is disposed on said driving shaft between at least one of a pair of said driving sections, said second flange roll member being axially symmetrical with a small diameter at each end thereof And being rotatably supported by at least two sets of needle roller bearings, each said set disposed at each small diameter end of said second member.
 9. A sectional forming roll according to claim 8, wherein said needle roller bearings are lubricated. 